OpenCAGE Model to OpenCAGE GUI Events
The Graph_Display_Controller (GDC) has observers attached to the Node_Model it represents, i.e. the background object of the GDC. It also has observers attached to every object that is shown in the Graph Window corresponding to the GDC.
The GDC listens to the following messages of its background object but ignores the other messages of the Node_Model_Observer:
- Destroying
The GDC destroys itself, too.
- Child_Added
The GDC creates a Node_Display and adds it to its children.
- Child_Removed
The GDC removes the appropriate Node_Display from its children.
- Child_Removed
The GDC removes the appropriate Node_Display from its children.
- Changed
The GDC updates its status bar.
The GDC listens to the following messages of the nodes shown in its Graph_Window but ignores the other messages of the Node_Model_Observer:
- Incoming_Edge_Added
The GDC gets the Edge_Display if it already exists, otherwise it creates the Edge_Display. Then it sets the end node properly.
- Outgoing_Edge_Added
The GDC gets the Edge_Display if it already exists, otherwise it creates the Edge_Display. Then it sets the start node properly.
- Incoming_Edge_Removed
The GDC sets the end node of the Edge_Display to null.
- Outgoing_Edge_Removed
The GDC sets the start node of the Edge_Display to null.
Node_Displays end Edge_Displays listen only to the following messages:
- Destroying
The display destroys itself, i.e. sending all its observer the "Destroying" Message beforehand.
- Changed
The display sends its observers the "Changed" Message.